Method and system for detecting and characterizing mechanical damage in pipelines using nonlinear harmonics techniques
US6239593A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 1998 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Sep 21, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/9046
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A nondestructive method for inspecting steel pipelines for plastically deformed regions caused by mechanical damage to the pipeline. The invention is a method and system that uses nonlinear harmonic detection methods to detect mechanical damage in pipelines. The invention uses a time-varying magnetic field to sense magnetic properties of the pipeline. The odd-numbered harmonic frequencies are detected and their amplitudes are related to the magnetic condition of the material under test to determine areas of mechanical damage. This technique can be used for rapidly surveying stress states in pipelines where nonlinear harmonic sensing devices are attached to a pigging device moving through a pipeline at a relatively high rate of speed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.